date times from before 1901 are converted to NA values

[aylapear]

There is a limitation on the size integers can be stored which causes the package fails as the integer goes over the allowed size, this occurs between "1901-12-13 00:00:01" and "1901-12-14 00:00:01" .

> as.integer(as.POSIXct("1901-12-13 00:00:01"))
[1] NA
Warning message:
NAs introduced by coercion to integer range 
> as.integer(as.POSIXct("1901-12-14 00:00:01"))
[1] -2147443199

This can be seen when using the dtt_date_time() function.

dtt_date_time("1901-12-13 00:00:01")
dtt_date_time("1901-12-14 00:00:01")

This is just a limitation of the package due to storing dates/times as integers, since this is core to the package this behaviour is not expected to be changed at this time.